textproduct: Quad Cities

KEY MESSAGES

- The remainder of the work week will be cooler than normal with a chance of rain just before the weekend.

- A pattern change this weekend will bring warmer than normal temperatures to the area next week.

SHORT TERM /THROUGH THURSDAY/

Issued at 158 PM CDT Wed May 20 2026

Dry easterly flow will keep temperatures cooler than normal tonight into Thursday. A passing upper level disturbance may or may not produce some sprinkles on Thursday.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

Issued at 158 PM CDT Wed May 20 2026

Thursday night through Friday night Assessment...high (>80%) confidence of a storm system. Low (20-30%) confidence on rainfall.

The remainder of the work week will be characterized by cooler than normal temperatures.

Timing differences continue regarding the system just before the weekend. What has changed over the past 24 hours are two items; 1) the track has shifted further east into the Ohio Valley, 2) the result of point 1 is that prolonged easterly flow that is deep and dry remains in place across the area.

The net result of these changes is that several deterministic model runs are strongly suggesting Thursday night and the first part of Friday morning could end up being dry across the area.

The model consensus is slowly trending this way by delaying the highest rain chances (55-70%) until late Friday morning through Friday evening. Additionally, the QPF is lowering as a result of the dry easterly flow. Most areas will see 0.25 inch or less with some areas potentially seeing up to one half inch. I would not be surprised if QPF amounts lower further over the next 1.5 days.

Sunday through Wednesday Assessment...a certainty (>95%) of warmer than normal temperatures

The holiday weekend still looks to be mainly dry although a rogue diurnal shower or thunderstorm cannot be ruled out.

As mentioned yesterday the flow pattern changes with southwest flow aloft developing as an upper level ridge develops on the east coast. The net result is temperatures climbing above normal starting Sunday and continuing through next week.

Starting Tuesday humidity levels will be much more noticeable and uncomfortable as dew points climb into the mid 60s. The increased moisture combined with the very warm temperatures and passing upper level disturbances is expected to result in mainly diurnal convection both Tuesday and Wednesday afternoon and evening. Right now the model consensus has rain chances at 15 to 30 percent.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1217 PM CDT Wed May 20 2026

Diurnal cumulus/stratocumulus will dissipate with sunset winds winds dropping to 10 knots or less. Winds are forecast to become easterly overnight and Thursday as high pressure moves into the upper Midwest.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.